Preparation

PREP: 40 minTOTAL: 55 min

Whisk lime juice and pineapple juice concentrate in small bowl. Gradually whisk in oil. Season vinaigrette to taste with salt and pepper.

Bring 6 cups water and next 4 ingredients to boil in heavy large saucepan. Reduce heat to medium; simmer 15 minutes. Reduce heat to low, add shrimp, and simmer until opaque in center, about 2 minutes. Drain. Transfer shrimp to large bowl; refrigerate until cool. DO AHEAD Can be made 6 hours ahead. Cover; keep chilled.

Mix mangoes and next 3 ingredients into shrimp. Pour vinaigrette over; toss to coat. Place 1 lettuce leaf on each of 6 plates. Spoon salad over lettuce, dividing equally.